Principal Component Analysis of HPLC-MS/MS Patterns of Wheat (Triticum Aestivum) Varieties

Untargeted metabolomic strategy was chosen to investigate as many small metabolites as possible in a collection of 13 varieties of conventionally grown spring and winter wheat and organic wheat (Triticum aestivum). Metabolites were separated by high-performance liquid chromatography on a reversed-phase column (RP HPLC) coupled with electrospray ionization tandem mass spectrometry (ESI MS/MS). The procedure includes extraction of metabolites followed by chromatographic separation using the linear gradient of aqueous formic acid and acetonitrile with subsequent identification of compounds by MS/MS. Discrimination of the metabolomic patterns of different wheat varieties was achieved by principal component analysis (PCA). Results of PCA indicated clear differences in the patterns of wheat varieties. The winter wheat grown in conventional conditions and the spring wheat grown in organic conditions differed from the spring wheat grown in conventional conditions by the higher content of carbohydrates. It could be explained by osmotic stress resistance. Varieties grown under organic conditions could be well distinguished from others by the results of PCA, which points to the existence of an impact of different farming systems.